Part of what I've been working on for Opera 10 is a new visual feature called Visual Tabs.
The new Visual Tabs goes hand in hand with the skin work we have been doing for Opera 10. Jon Hicks, now a Lead Designer with the Consumer division at here at Opera, has been the (evil? ) master mind behind this work and you can also see the initial progress of that work in this first beta.
What we have seen in the past is that the thumbnails that shows up when hovering tabs has been useful and popular among our users.
Taking the work that was introduced in Opera 9 a step further makes Visual Tabs the natural next step.
For this beta, they are not shown by default but can be enabled by dragging down the drag bar just beneath the tabs themselves. You can also double click the drag bar or middle click it show/hide the Visual Tabs completely.
Our goal has been to make something that is visually pleasing, yet remains useful for people that have a handful of tabs open and needs an easy and visual way to always know what site is on what tab.
What you see in this first beta is a first step, and there will most likely be tweaks and changes made to the current solution to address issues and feedback from our users.
If you absolutely do not want to see any sign of them, they can be disabled quickly and easily by right-clicking on the tab bar or an active tab, select Customize->Enable thumbnail previews.
We are open to suggestions on how to improve this feature.